Selector switch



A Sept. 28 1926.

c. H. BERRY SEPECTOR SWITCH FiledI Nov. 21 1924 v Latem@ Si@ Patented Sept. 28, 1926.

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SELECTGR SWITCH.

Application nled Noieinber 21 1924. Serial No. 751,217.

This invention relates to telephone apparatus of xthe automatic ,type and more particularly to selector switches used in .antom-atic tclephone'exchange systems wherein a' :call from a calling"subscribers 'line is routed through .a selector switch by a 4conornon. sender mechanism. @ne .of the lobjects of .this invention is 'to provideA a circuit @for `autcun-atically returnv ing. #to normal a selector switch which has been movedofinormal hand .or-advanced talsely the brush .Slaat-t oli. normal.

Another object is` the 4 employment of a cirouitwhich .makes it :possible for a single revolution of, the sequence .switch associated 'vv-ith fa selector switch to ltaire care ot two successive calls.

-Heretotore ifselector switches were abnorrnally A.operated[by Ithe jarring ot the mechanism .-during normal operation of the associated parts `or the4 carelessness of kwor-lnien, the switches Weremanually restored to normal. This ,necessitated the lenrploynient of attendants whose duty vwas to restore abnormally :operated selector switches. In accordance 'with one .oi the objects oi' Ythe presentl invention such lconditions are obviated 'by pfoviding means for thev autoinitiol `restoration ot abnormaliy yoperated switches. A sequence :sw-itchiorming part of the v control circuit oi a selector switch which utilizes all of its positions, that is, takes a single .complete revolution foreach c-all 2in which the selector is employed` is Welllrnown in the art. lgcovrever,y by provi'ding,v in accordance with the .presentinvention, a acircuit which makes it 1possible to :double Vthe call capacity oi a selector sequence switch` byV utilizing .a singie revolution of the switch for'n'ialring two successive calls, the wear on thesequence switch is halved thus doubling the Blite oi' the switch.

in order that the presentinvention may be lmore readily understood, the characteristic features oi' the portions of the vantomatic telephone exchange system to which thepresent invention relates, wili be brietly described, the system being .described in deta'il in thepatent to F. A. Stearn, No. 1,505,- lY'l `,`isis'-ued"Aug. i9, 1924. For this purpose reference may be had to the accompar" drawing which shows diagrammati x g and salted subscribers suitch, sender, district, .incoming and `final selectors, and in detail the circuit oit.' an oliice selector embodying the lfeatures oit the present invention.

` ,A calling subscriber upon removing his receiver. from the hook 'is connected to a line switch of which there is one for .each line connected to the exchange. The line switch automatically selects an idle .Circuit which leads to a district selector. As Soon as the line switch selects va .non-busy district circuit, a sender selector automatical'lylY se- -lects a sender. The operation lof the dial .the calling subscribers station stores the impulses representing the Vexchange and line number wanted on registers ,in the .sender referred to above. ,The-sender havmgreceived and .stored all ot" the impulses from the dial automatically controls the setting of the district v,selector to select an idle trunk going tothe desired oiiice. The sender then .controls the setting ot' an otlce selector in which the selectedtrlmk terminatos, which locates an idley ,trunk toan Aincoming selector in ythg-i distant fotiicef* The incoming selector is then. controlled by the .sender to ychoose `ahnalselector on which .the desired number is located, the -fina'lselector then being operated vto select lthe desired line. .The various sender registers control the choice of the desired number. There is only one vpartot this automatic telephone exchange, system above outlinedwhich properly constitutes the present invention, that is, the oiiiceselector .circuit employing a'v sequence .K switch which automatically frcturns to normal and is ycapable ,of i carrying through two successive calls in a single rev- .:ma-l, a relay operates byy means of an energizing circuit prepared by the off normal condition which in turn energizes the sequence switch magnet moving the sequence switch to` the next position when the relay releases. in this position of the sequence switcl'i an energizing `circuit is closed which adif'ances it .to the ner" I "sition lWhere said ay again oneratris, s'. is., n

until that position of the sequence switch is reached in which the down drive magnet of the selector is energized, causing the brush shaft to return to normal. rhis normal condition of the brush shaft closes an energizing circuit which advan the sequence switch to a normal position.

lleans are provided in this invention for automatically controlling a cycle of circuit changes in a definite sequence for controlling the selector by means of a sequence switch, one revolution of which takes care of two cycles for two successive calls.

The operation of the circuit is as follows: Upon the calling subscriber at A1 removing `his receiver from the hook, and dialing his number, a district selector is connected to terminals 105, 100, and 111 of the oliice selector in a manner well known in the art. In the present invention this occurs when the sequence switch is in normal positions 1 or 10. fr fundamental circuit is closed from grounded battery 100, through the left contact of cam 101, left winding of relay 102, the lower left contact of cam 103, the left contact of cam 101 over the tip side of the Jfundamental circuit to the associated distr'ct and sender circuits, back over the ring side of these circuits through right lower contact of cam 10i to ground. operating relay 102. The operation of relay 102 closes an energizing circuit for the sequence switch magnet 10S which may be traced from ground controlled by the district sleeve terminal 11st, the upper contact of cam 109, contact 110 of operated relay 102, lower right Contact of cam 111, through the sequence switch magnet 10S, battery 112 to ground, the sequence switch 113 advancing to position 2 or 11. As the switch enters position 2 or 11, ground from the left and rightupper contacts of cam 109 is connected to the district sleeve terminal. 11-1 holding` the otlicc selector trunk busy to all other district selectors. rllhis busy ground is effective in positions 2 to 21/3 and to T or 11 to 11% and 12% to 1G. 1n positions 21/2 to 31/2 or 111,/Q to 121/2, the busy condition is produced by the resistance of the right winding of relay 102 to ground at cam 129. The relay 102 is now held operated over the fundamental circuit over the upper left contact of cam 103, armature springs 13S and 132 and left winding of relay 102 to battery at the left contact of cam 101.

In position 2 or 11, the up drive magnet 11S of the selector is energized for brush selection. This energizing circuit goes from ground through the left contact of cam 109, contact 110 of operated relay 102, thc right upper contact of cam 111 through up drive magnet- 118, battery 119 to ground. As the brush shaft moves upward, a circuit is closed from ground over the lower contacts of cam 129, eommutator brush 121, commutator segment 120, and upper contacts of cam 103 over which ground pulses are sent back over the fundamental circuit to successively short circuit and permit the reoperation of the stepping relay in the associated sender circuit until the proper brush has been selected. Then sutlicient pulses have heen sent back to satisfy the sender, the fumlanienfg-.zl circuit is opened and relay 102 releases. The release of relay 102 opens the circuit through up drive magnet 11S which deenergiyx and stops the upward movement ot the switch shaft. The release of relay 102 also closes an energizing circuit for the sequence switch magnet 10S which may be traced from ground through the left contact of cam 109, normally closed contact Y122 of relay 102, right lower contact of cam 1223, through sequence switch magnet 10S to liiattery 112 and thence to ground. The sequence switch advances to position 3 or 12. lVhen the switch reaches position 21/3 or 111/2, ground from the district sleeve is closed through both upaer contacts of cam 125 to hold the right winding of relay 102, shunted at this time.

their the switch reaches position 3 or 12, the fundamental circuit is again closed through the left winding of relay 102. lielay 102 operates and closes :in energizing circuit for sequence switch magnet 10S, the switch advancing to position et or 13 for group selection. The energizing circuit for sequence switch magnet 10S may be traced from ground through left contact of cani 109, contact 110 of operated relay 102, lower right contact of cam 111, sequence switch magnet 10S, battery 112, thence to ground. rfhe trip magnet 126 is energized in positions 3 to 5 or 12 to 1l1 from ground through both lower contacts of cam 109, trip magnet' 120, battery 119, and thence to ground. lilith the switch in positions a'- or 13. relay 102 is leld operated over its left winding and left contacts 132, 138, the left contact of cani 10?) and the fundamental circuit traced. and the up drive magnet 11S if: again energized from ground through the left Contact' o1 can 109, contact- 110 of operated relay 1 right upper contact of cam 111, through the up drive magnet 11S, battery 119, to ground. The trip magnet 120 being operated canso: the previously selected brush to trip s the brush shaft moves upward for group scie-t tion.

AS the brush Shaft moves upward for group selection, a circuit is closed from ground at cam 129 through coinniut'atnr lili) ist 1,058'

mental circuit is opened, releasing relay 102. The release of vrelay 102 opensthe circuit through the up drive magnet 118 and closes a circuit for advancing the sequence switch to position 5 or 14, the energizing circuit for the sequence switch magnet .108 being the same as that traced for advancing it to position 3 or 12.

With the sequence switch in position 5 or 14, ya circuit is closed from ground through the lower left and ripper right contacts of cam 129, right winding of relay 102, resistance 115, battery 117 ,f to ground, operating relay 102. The operation of relay 102 closes an energizing circuit for the sequence switch magnet 108 which is similar to that traced for position 3 or 12.` The sequence switch advances to'position 6 or 15. Then the sequence switch reaches position 6 if the ii-rst trunk of the group in which the selector hunts is busy, relay 102 is held operated through its left winding to ground onthe sleeve terminal 141 ofthe busy trunk. This circuit may be traced from ground on sleeve terminal 141 of they trunk, brush 140, conductor 131, through the right contact of cam 130,' contact 132 of operated relay 102, the left winding of that relay, the left contact of cam 101, battery 100 to ground. As long as relay 102 is held operated due to this busy condition, the circuit to the up drive magnet 118 is maintained from ground through the left contact of cam 109, contact 110 of operate-d relay 102, upper right contact of cam 111, the up drive magnet 118, battery 119 to ground, and the brush shaft will .travel upward until an idle trunk is found. `When, an idle trunk is found, the circuit through the left winding of relay 102 is opened but the relay will not` release immediately, .due to a holding circuit being closed from ground on commutator segment 127 and .commutator brush 1 28, through both upper contacts of cam 129, right winding of relay 102, resistance 115` batteryV 117 to ground. When the circuit through commutator segment 1 33 is opened upon the switch brushes becoming properly centered on the terminals of the selected trunk, relay 102 releases, opening the'circuit through the up drivemagnet 118, which stops the selector brushes on the terminals of the. selected trunk. lThe release of relay 102 also closes a circuit for advancing the sequence switch to position 7 or 16v thecircuit being the same Ithat was traced for position 4 or 13. y

1f all the trunks in a group are busy, the selector brushes travel-over the top yof the group .and rest on the overflow terminals. As there is no ground on the sleevel of the overflow terminals, relay 102 will release and cause the switch tovadvance to position 7 or LA16 in .which position relayy 10.2again operates troni ground on 'earn 130 and leales to a ground on cam 109 as described hereinbelow advancing` the switch to position 8 or 17. In position 8 or 17, a circuit is closed from ground on commutator brush 121 and commutator segment 120, the lower left contact of cam 123, sequence switch magnet 108, battery 112 to ground advancing the switchto position 9 or 18. When the switch advances to position 9 or 18, battery 117 is 'connected through resistance 116, through leftV contact of cam 107 over the ring conductor 106 through the district and overiiow relay of the sender circuit back over the fundamental tip conductor through the left contact of cam 104,left upper contact of cam 103, contacts 138 and 132 of operated relay 102 to the low-er left contact of cam 130 and thence to ground on the district sleeve terminal 114. This circuit advances the sender and district and when the district sleeve is opened, relay 102 releases. rEhe release of relay 102 connects ground to the down drive magnet 136 returning the lircuit tov normal.

When all the trunlrs in a group are not busy anfl the brushes are brought to rest on the terminals of an idle trunk with sequence switch 108 in position 7 or 16, relay 102 operates in a circuit which may be traced from ground through normally i closed contact 137 of relay 102, or from the district sleeve and the lower left contact of cam 130, left upper contact of cam 130, left winding of relay 102, right contact of cam 101, right winding of relay 10,2, resistance 115, battery 117 to ground. The operation of relay 102 again closes a circuit for advancing the sequence switch to position 8 or 17. Uien operated in position 7V or 16, relay 102 locks to ground at 'cam 109 over a circuit which may be traced from ground through the left and right ripper contacts of cam 109, left lower Contact of cam 130, contact 132 of relay 102, yleft winding of relay 102, right contact of cam 101, right winding of relay 102, resistance 115, battery 117, and thence toV ground. In positions 8 to 9 or 17 to 18, relay 102 locks to ground on the sleeve brush of the associated district circuit. In position 8 or 17, the tallring-circuit is closed through both lower contacts of cam 104 and the upper right contact of cam 107.

Y At 'the completion of the conversation, the district selector is disconnected from the follice selector opening the circuit through the windings of relay 102 which releases. lVhenrelay 102 releases, ground is connected to the sequence switch magnet 108, advancing it to position 9 or 18. In position 9 or 18, ground is connected to down drive magnet 136 energizing the down drive lo return the brush shaft to normal. This circuit may be traced from ground through the left cantati 'cara 109, normally contact 122, of relay 102, both lower contacts of cam 125, down drive magnet 136, battery 110 to ground. vWhen brush shaft reaches the bottom of the bank, ground from commutator brush 12S and commutator segment 180 is connected to sequence switch magnet 108 through the upper right contact of e m 1257, advancing the switch to normal posi .on or 1.

Vfhen the brush shaft is driven to telltale, a circuit closed from ground on connnntator s ginent 131 and brush 12S through the lett upper contact of cani to battery 112. through .sequence switch magnet 10S :ul-.'ancing the switch to position T or 10, yllhe operation of relay 102 in position or 10 advan'es the sequence switch to position S or 1?. The ground on commutator segment 131 and commutator brush 128 advances the switch to position 9 or 1S. From this point on, the circuit functions in the same manner as previously described hereinabove for the overflow condition where all the trunks in a group are busy.

The self-returning feature of the sequence switch in a position awaiting a sender for group selection (position 3 or 12) will now be described in detail. Suppose the sequence switch 10S or the selector switch be moved eti' normal by hand or the sequence switch be advanced to position 3 or 12 falsely with the brush shaft olf normal, the connnutator brushes being above commutator segment 130, with no district selector connecte-l to the incoming conductors 105, 10G and 111. RelL v 102 will operate in a circuit from ground through the lower left and upper right contacts of cam 129, right winding of relay 102, through resistance 115, hattery 117 to ground. rlhe operation of relay 102 closes an energizing circuit for sequence switch magnet 10S which may be traced from ground through battery 112, magnet 108` lower right contact of cam 111A contact 110 of operated relay 102, left contact of cam 100 to ground. The sequence switch advances to position 11 or 13 in which position relay 102 releases and the magnet 10S is again operated in a circuit from the left contact of cam 109 through the normally closed contact 122 of relay 102. lower right contact of cam 129, through magnet 10S to grounded battery 112. rl`he switch advances to position 5 or 1-1 in which position relay 102 again operates in a. circuit similar to that traced for position 3 or 12. Sequence switch magnet 10S energizes advancing the sequence switch to position G or in which position, relay 102 again releases. whereupon the sequence switch magnet 10S is again energized in a circuit the saine as described above for position et or 13. rhe sequence switch advances to position '7 or 1G, relay 102 operating in a circuit from ground through battery 11T, resistance 115, the right winding of relay 102, right contact of cam 101, left winding of relay 102, upper left conact. of cam 130, normally closed contact 13T of relay 102 and thence to ground, relay 102 locking through its windings, the left contacts of cam 1230 to `ground through the upper right and lower left contacts of cani 100. Sequence switch magnet 10S is energif/ied and advances the sequence switch to position 8 or 1T, in which position relay 102 releases, whereupon the sequence switch magnet 10S is energized advancing vthe switch to position 9 or 1S. 1n position 0 to 1", the down lrive magnet 13o is operated in a circuit which may be traced from ground through the left contact of cam 109 to the normal closed contact 122 of relay 102, both lower contacts ol cam 125 through down drive magnet 130 to grounded battery 110. rfhe operation of down drive magnet 130 causes the brush shaft to go down to normal. Vfhen the brush shaft reaches the bottom of the bank, ground on the commtdator brush 12S and "ment i: t) is connected through the upper it contact oi cam 123 to the sequence nomaL 1i lVhat claimed is:

1. 1n a telephone exchange system, a calling subscribeus line, a called subscribers line, automatic means for extending a call from said call'ig subscribefs line to said called suhscribeus line including a selector switch, said switch having progressively operable means individual thereto for con trolling two complete cycles of operation thereof duringa single complete cycle of said last named means.

2. 1n a telephone exchange system, a calling subscribers line, a called subscribers line, automatic means for extending a call from said calling subscribers line to said called subscribers line including a` selector switch, said switch having an auxiliary progressively operable switch individual thereto for controllingtwo complete cycles of operation thereof during a single revolution of said auxiliary switch.

In a telephone exchange system, a calling subscribeus line, a called subscrihers line, automatic means for extending a call from said calling subscribers line to said called subscribers line including a selector switch, said switch having progressively operable means associated therewith for controlling two completc cycles of operation thereof during a single complete cycle of said last named means, and means associated with said switch including a i'elay operative in response to an energizing circuit prepared by an abnormal off-normal condition of said switch for automatically restoring said switch to a normal position.

4l. In a telephone exchange system, a calling subscribers line, a called subscribers line, automatic means for extending ra call from said calling subscribers line to said called subscribers line including a selector switch, said switch having a progressively operable switching means associated therewith for controlling the setting and restoration thereof, and means for causing the restoration of said switch including a relay whichv is repeatedly operated during the advance of said switching means and controls the advance of said switching means to its switch restoring position.

5. In a telephone exchange system, a calling subscribers line, a called subscribers line automatic means for extending a call from said calling subscribers line to said called subscribers lineV including a selector switch, said switch having a progressively operable switching means associated therewith for controlling the setting and restoration thereof, and means for causing ther restoration of said switch including a relay which initially operates to advance said switching means, the advance of said switching means causing the release of said relay, said release causing the further advance of said switching means, this cycle being repeated until said switching means is advanced to its switch restoring position.

6. In a telephone exchange system, a calling subscrihers line, a called subscribers line, automatic switching means for extending a call from said calling subscribers line to said called subscribers line including a selector switch, means associated with said switch for restoring it to normal position, a relay means effective when said switch is moved to an oil-normal position and no other of said automatic switching means is connected therewith for operating said relay, and means under the control of said relay for operating said restoring means.

7. In a telephone exchange system, a` calling subscribers line, and a called subscribers line, a selector switch for extending aconnection from said calling line to said called line, a sequence switch associated therewith for controlling its operation, having two normal positions, and means associated with said sequence switch for automatically restoring it to one of said two normal positions from a position to which it has falsely advanced.

In witness whereof, I hereunto subscribe my name this 18th day of November A. D.,

CLARENCE II. BERRY. 

